title: Prevalence of Listeria monocytogenes in poultry production in France.
abstract: This study aimed to update and create a data set from laying hens and broilers regarding contamination by Listeria monocytogenes. Two hundred laying-hen flocks were sampled, with 88 flocks reared in cages and 112 reared on the floor. One hundred forty-five broiler flocks were sampled, with 85 conventional and 60 free-range flocks. A total of 774 and 725 samples were analyzed from laying hens and broilers, respectively. L. monocytogenes was detected in 31 of 200 flocks, yielding an estimated prevalence of 15.5% in laying-hen flocks. Among positive flocks, there appeared a significant (P = 0.004) difference between caged and floor-reared hens, with a higher detection in dust samples from floor-reared hens. In positive caged hen flocks, significant (P = 0.028) differences between dust and fecal samples appeared, with a higher detection in feces than in dust samples. In broiler flocks, L. monocytogenes was isolated in 46 of 145 flocks, yielding an estimated prevalence of 32% (28% in conventional flocks versus 37% in the free-range flocks). L. monocytogenes was isolated in samples taken from conventional flocks with a lower frequency than in free-range flocks (13 versus 18%, respectively). The serotyping of L. monocytogenes strains showed that the majority belonged to type 1/2a in laying-hen flocks (74.3%) and in broiler flocks (40.5%). A significant difference (P = 0.007) between laying hens and broilers was shown for serogroup 4 and for serovar 1/2b (P = 0.007); these serogroups were more prevalent in broilers (40%) than in laying hens (5.7%).
authors.affiliation: Laboratoire d'Etude de Recherche Avicole et Porcine, Unité Hygiène et Qualité des Produits Avicole et Porcin, BP 53-22440 Ploufragan, France. m.chemaly@ploufragan.afssa.fr
authors.forename: Marianne
authors.initials: M
authors.lastname: Chemaly
authors.forename: Marie-Therese
authors.initials: MT
authors.lastname: Toquin
authors.forename: Yolene
authors.initials: Y
authors.lastname: Le Nôtre
authors.forename: Philippe
authors.initials: P
authors.lastname: Fravalo
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D002645:Chickens / Q000382:microbiology*; D004197:Disease Reservoirs / Q000662:veterinary; D004391:Dust; D005243:Feces / Q000382:microbiology; D005260:Female; D005506:Food Contamination / Q000517:prevention & control*; D005602:France / Q000453:epidemiology; D006799:Housing, Animal; D008089:Listeria monocytogenes / Q000145:classification / Q000302:isolation & purification*; D008088:Listeriosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D008297:Male; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology; D015995:Prevalence; D012703:Serotyping / Q000662:veterinary
chemical_list: D004391:Dust